The Vertical City – Norman Foster

The skyscraper is emblematic of the modern- age city and is a reminder that the city is arguably civilization’s greatest invention. A vertical community, well served by public transport, can be a model of sustainability, especially when compared with a sprawling, low-rise equivalent in a car-dependent suburb. Our own design history of towers is one of challenging convention.

We were the first to question the traditional tower, with its central core of mechanical plant, circulation and structure, and instead to create open, stacked spaces, flexible for change and with see-through views.

The ancillary services were grouped along-side the working or living spaces. This led to a further evolution with the first-ever series of “breathing” towers. In the quest to reduce energy consumption and create a healthier and more desirable lifestyle, we showed that a system of natural ventilation moving large volumes of fresh, filtered air could be part of a controlled internal climate.

My fascination with the tall building began with a design assignment in the Master’s Class of 1962, at the Yale School of Architecture. Despite a previous five years as a student, it was the first time I had been challenged by a tower, and I felt the need to go back to first principles, starting with the structure. I asked the Dean, Paul Rudolph, if he could find me an engineer to work with. This was an unheard-of proposition. The cult of Yale, like so many schools, was that the architect designed a building, and then, afterwards, the engineer would make it stand up. To the credit of Rudolph, despite his beliefs, he found me an engineer who would work alongside me.

As we started a dialogue together, it quickly became obvious why every tall tower from the birth of the high-rise onwards had a central core. It combined structure with vertical circulation, bathrooms and mechanical services for heating and cooling. It was so logical that it was perhaps obvious why it had never been questioned. However, the occupants in such a concept are forced to occupy a restricted perimeter strip around the core with one-way views outwards. What if, I argued, the core was fragmented and its separate elements placed alongside flexible, open, loft-like floors, with cross views on the two long sides. This led to a design which the later Dean, Robert Stern, would suggest was the genesis of our tower in Hong Kong for the Hongkong and Shanghai Bank, designed in 1979 and opened six years later.

This project was the first in a succession of towers that have effectively reinvented the skyscraper by exploring alternatives to the historic central-core model. In the 2023 exhibition of our works in the Centre Pompidou I lined models of these diverse towers next to the long window wall – a play on the skyline of Paris, visible in the distance. This part of the show was titled Vertical City, and a selection from it forms the basis of the Hearst exhibition.

The visual dynamic of clusters of tall towers and the cities that generate them are inseparable from the dramatic profiles of their skylines. However, coming down to earth, the connection of a tower with the urban fabric at its base is critically important. It is an opportunity for the private world within the tower to engage with the local community – to give back some social benefit to the city that is the host.

For example, the Hong Kong tower is elevated above the ground to provide a significant public space as a shortcut under the building. It acts as an extension of the park that fronts the headquarters and, in a dense city, provides valuable breathing space.

The Commerzbank Tower in Frankfurt similarly engages with the public domain by providing a public route through its base. This urban interchange features a restaurant open to the public and bank employees alike. A low-rise podium knits into the scale of the surrounding streetscape.

Coming back to the exhibition venue, the Hearst Tower not only recycles a historic 1928 Art Deco base, but also brings the sidewalk to life by returning traditional uses to the ground level. Hollowed out from within, it creates the equivalent of a town square, bringing together the diverse groups through restaurants, exhibitions and gathering spaces.

Still in New York, the cantilevered structure of the JPMorgan tower doubles the amount of public space at its base compared with its predecessor. Like the Hongkong Bank and JPMorgan, the identity of the Hearst Tower is the expression of its structure. Here the diagrid of recycled steel saves some 20% of structural weight compared with a conventional structure.

Our evolution of the tall tower has a sustainable agenda. For example, the Hongkong Bank broke with the conventional glass box by introducing external shading to reduce the solar gain and energy demand. The Commerzbank Tower that followed was a high-rise “first” with its opening facade that creates a climate-controlled, naturally ventilated interior – combining wellness with lower energy consumption. All the skyscrapers that followed, including the Hearst Tower, were marked by enhanced natural ventilation – in some instances double the code standards – to create an exceptional indoor air quality. Here the health of the occupants overlaps with that of the planet.

On the subject of the environment, I am sometimes challenged by the question of “how can a tall tower ever be sustainable?” My answer is to show them a recent map of the East Coast of America prepared by two researchers from the University of California, Berkeley. It is color-coded to show, area by area, the carbon footprint. Red shows the extreme high and dark green marks the lowest. At first glance it is dominantly red, but on closer examination there is a dark green spot marking Manhattan, a true vertical city standing out from its background of suburban sprawl. New York, for a variety of reasons, especially for its walkability and lack of dependence on the car-borne commute, is an island of relative sustainability that is inseparable from its dense verticality. The most sustainable can also be the most desirable. New York topped the sixth-annual list of the “Best Cities in the World,” released by Time Out in January 2024.

Norman Foster

Founder & Executive Chairman,
Foster + PartnersPresident, Norman Foster Foundation